Particulate matter - This is the term for solid or liquid particles found in the air, which help create smog. They can be very small and can travel deep into your lungs, causing breathing and heart problems.

Carbon monoxide (CO) - This is a colourless, odourless gas that is poisonous at high levels. It can make you feel sick and even kill you.

Volatile organic compounds (VOCs) - These are a wide range of compounds that usually have no colour, taste or smell. Some cause direct health effects, while others contribute to smog.

In communities where wood heating is common, wood smoke can be responsible for as much as 25% of the airborne particulate matter, 8% of the VOCs, and 7% of the CO in the air.

Wood smoke also contains small quantities of other toxic compounds, including nitrogen oxides and chlorinated dioxins. These can contribute to environmental hazards, like smog and acid rain.

Health risks

Wood smoke can cause eye, nose, and throat irritations, as well as headaches, nausea, and dizziness. It can make asthma and other breathing (respiratory) problems worse.

Smog, to which wood smoke can be a significant contributor, has been linked to severe health risks, including increased hospital admissions and even premature death.

Wood smoke can affect anyone, but these groups are especially vulnerable:

people with heart or lung problems

children, because their respiratory systems are still developing and they tend to be more active and inhale more air

Safety tips

Help reduce the environmental and health impacts of wood smoke by following these tips:

Switch your heating source. Switch to a different source of heating, like natural gas or oil.

Choose a low-emission stove. Install an "advance combustion" wood stove or fireplace insert to reduce toxic emissions. Look for appliances that have a sticker from the United States Environmental Protection Agency (EPA). This sticker certifies that the appliance emits up to 95% fewer particulates and is up to 20% more fuel-efficient than regular models.

Maintain your stove. Make sure that your wood stove is well maintained and working properly. Have it inspected by a qualified professional at least once a year.